When members of a building construction are subjected to horizontal external forces, the members are twisted or horizontally moved. In particular, the twisting generated in a building construction or a tower may cause severe shocks or collapse of the building construction or the tower.
A damper plays an important role in protecting a building construction, for example, a house or the like, and exists in numerous modified forms.
The damper attenuates movement by a frictional force between two movable parts fixed between members of a construction structure or a fluid moving between two chambers through a limited tube.
Some dampers are active dampers that actively change an attenuation effect corresponding to an external state and others are passive dampers that have predetermined attenuating characteristics.
However, the conventional dampers are costly and much higher costs are required in assembling the dampers with members of a building construction.
In addition, when friction plates mounted to offer a frictional force are abraded, the friction plates capable of attenuating a vibration may be functionally degraded and the entire damper structure is necessarily replaced, thereby resulting in increased maintenance and replacement costs
In addition, since the conventional damper, particularly, the friction damper, is designed to absorb vibration energy while moving with a constant frictional force, it cannot effectively cope with external forces (loads) of various magnitudes.
That is to say, in a case of a friction damper having great friction durability, since the friction damper is not driven by a small external load such as a small scale earthquake or a vibration due to a wind, it may not function as a damper.
Conversely, in a case of a friction damper having small friction durability, since the friction damper is not driven by a large external load such as a large scale earthquake, it may not properly attenuate vibration energy.